Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds context about freshness floors, error semantics (explicit error, not empty success), billing behavior (not billed for errors), and demo mode behavior with per-IP limits. However, it doesn't detail rate limits beyond per-IP, or what happens when the limit is reached, leaving some behavioral ambiguity.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single well-structured paragraph that front-loads the core purpose and key pairing, then covers error and demo modes. It is dense but not bloated; every sentence adds useful information, though a bit long. It earns a 4 for being efficient yet packed with relevant details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (4 params, no output schema, but annotations cover safety), the description provides essential usage context: scoping, error behavior, billing, and demo access. It lacks details on return format (no output schema) and specific parameter formats beyond the pair, but these are partially covered by the schema. Overall, it's sufficiently complete for an agent to invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema description coverage is only 25%, so the description must compensate for the undocumented `req_key` and `company_id`. The description clarifies the pair semantics ('every `search_jobs` row already carries') and mentions `plane_api_key` is deprecated via schema, but the description doesn't elaborate on `idempotency_key` or provide syntax details for `req_key` or `company_id`. Since it partially compensates but not fully, a 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description precisely states that this tool retrieves a single open role's details using the `company_id` + `req_key` pair, and explicitly contrasts it with `get_open_reqs` which pulls the whole company. This makes the tool's purpose unambiguous and distinct from siblings, especially `search_jobs` and `get_open_reqs`.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says this is the 'follow-up call for a role you hold an identifier for, instead of re-pulling the whole company with `get_open_reqs`. It also provides guidance on error conditions (non-existent, closed, or not yet fresh roles) and demo mode usage (omit header for free calls). This gives clear when-to-use vs alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.